Figure 4.

Regulation of Ambn expression in dental epithelial cells by gap junction communication. (A) Immunostaining of Cx43 (red) and nuclear staining with DAPI (blue) in cultured dental epithelial cells. The cell marked with an asterisk contacts six cells via gap junctions. (B) The average number of contact cells at each cell density is shown in the left panel. Expression of Cx43 in cultured dental epithelial cells at each cell density is shown in the right panel. (C) Expression of Ambn at each cell density with or without the gap junction inhibitors 18α-Glycyrrhetinic acid (18α-GA) and oleamide. (D) Effect of gap junction inhibitors on Cx43 after 48h of TGF-β1 stimulation (1ng/ml). (E) Effect of the gap junction inhibitors 18α-Gly and oleamide on Ambn expression (left panel) or on Cx43^−/− cells (right panel). (F) Gap junction activity was measured by transfecting dental epithelial cells with a Cx43 expression vector carrying R76S or R202H mutations. CalceinAM and DiI were injected into the center of cell. Ambn expression in cells stably transfected with Cx43 expression vectors harboring R76S or R202H mutations, which are found in human oculodentodigital dysplasia (ODDD) patients, after stimulation with TGF-β1 is shown in the right panel. ^**p<0.01.